Fresh-cut technology involves many operations that might cause metabolic alterations in the processed tissue such as increase in respiration rate and ethylene evolution. Respiration is a complex process in which organic compounds are oxidized to carbon dioxide and water, with energy release. Ethylene evolution is also very important and can be observed in fresh-cut vegetables crops. In the present work we studied the physiological effects associated with fresh-cut lettuce (Lactuca sativa L.) searching the best temperature for storage as well as how the stress caused by processing affects the product. It was observed that right after processing respiratory rates of the materials sliced at 5 and 10mm thick were statistically different from the lettuce processed for both 5 ºC and 10 ºC storage temperatures. Storage at 5 ºC was capable of reducing the metabolism faster when compared to the storage at 10 ºC. The respiratory activity and ethylene evolution curves profile for the lettuce processed at 10 mm were the same for both the studied temperatures, differing only for the values, that were higher, as expected, for 10 ºC. Ethylene evolution reduced for the material processed at 10 mm and stored at 5 ºC, but did not reduce for the material processed at 5 mm at the first two hours after processing. The best temperature for fresh-cut lettuce storage was 5 ºC and the material processed as whole leaves showed the lowest levels of carbon dioxide and ethylene evolution.
Minimally processed; lettuce; ethylene; respiration; Lactuca sativa
